Influence of Oxide Content in Activated Tungsten Inert Gas Welding

In this paper, welding-remelting of AISI 304L (X2CrNi19-11) austenitic stainless steel was performed by using TIG process with activating flux, that is, A-TIG process. Fluxes were prepared by mixing 5, 10, 20, 30 and 40 % SiO2 nano particles with acetone solvent, while the application of the flux was done by a brush, prior to electric arc engagement. Characterization was done by visual testing and macro section analysis, with the main stress aimed at penetration depth as the dominant parameter used to assess the effectiveness of the flux. It was found that the highest penetration was obtained with 5 and 40 % of nano particles, with the wider weld obtained with 40 % of nano particles. However, from the point of welding technology, it was assessed that this is of secondary importance and that the optimal flux contains 5 % nano particles, primarily due to a lower cost, simpler mixing, lower viscosity and an easier flux application on the base metal.